Sorry for the late reply. I was raised in Firth; just down the road from IF. My oven is built on a 6 inch thick concrete pad with steel in it and over pit run and then gravel. No problems yet. I am almost done; only about 1/3 of the roofing left. We have cooked over 300 pizza since last fall. It is a blast cooking in a wood fired oven. Let me know if you have any other questions.